1. Field of the Invention
The present invention relates to a both-side recording apparatus capable of both-side recording on a recording sheet of which front side and back side are inverted by a sheet inverting unit, and also to a both-side recording apparatus provided with a sheet feeding roller, a recording unit and a sheet inverting unit.
2. Description of the Related Art
For automatic both-side recording in an ink jet recording apparatus, several methods have been commercialized or proposed in several methods. In these methods, after recording on a front side (top side) of a recording sheet, the conveying direction thereof is reversed to feed the recording sheet into a front-back side inverting apparatus, and, after an inverting operation, the recording sheet is conveyed again by the same sheet conveying unit to execute recording on the back side of the recording sheet by the same recording unit.
Among these methods, U.S. Pat. No. 6,332,068 discloses an invention in which the front-back side inverting apparatus is provided at an upstream side of a sheet conveying roller and the conveying direction of the recording sheet is inverted by 180° by two inverting rollers positioned above and below. Also Japanese Patent Application Laid-open No. 2002-067407 discloses an invention in which the front-back side inverting apparatus is provided at an upstream side of a sheet conveying roller and the conveying direction of the recording sheet is inverted by 180° by a roller of a large diameter, principally executing the inversion, and an auxiliary roller of a small diameter.
However, these prior examples have been associated with certain limitations.
In the invention disclosed in U.S. Pat. No. 6,332,068, since a sheet conveying path to the front-back side inverting apparatus is not present on an extension of a sheet conveying path connecting the sheet conveying roller and a sheet feeding roller, a recording medium of a large thickness or a high rigidity cannot be passed to the sheet conveying path to the front-back side inverting apparatus.
Also in the invention disclosed in Japanese Patent Application Laid-open No. 2002-067407, the sheet conveying path to the front-back side inverting apparatus is present approximately on an extension of the sheet conveying path connecting a sheet discharge roller and the sheet conveying roller but has a meandering shape, so that a recording medium of a large thickness or a high rigidity cannot be passed to the sheet conveying path to the front-back side inverting apparatus as in the above-described case. Also the rollers of the front-back side inverting apparatus are concentrated above the sheet conveying path connecting the sheet discharge roller and the sheet conveying roller, so that the dimension of the apparatus has to be made large in order to secure a necessary length for the sheet conveying path.